Abstract: A system for checking the presence of one or several words from a given list in an input put string of subwords. The list of words is stored in a memory array comprising one comparator for each memory cell storing one subword. The string is divided in sub-strings. Each sub-string is loaded several times unto a compare register, each time being roll-shifted by one sub-word. At each memory cell, simultaneous comparisons are made with the input sub-string. A logic circuit for each memory cell detects consecutive matching of sub words of the string with the sub-words of a word of the list. Whenever a match occurs for a full word of the list, a signal is set for for this word. A List Match signal is set, and a priority encoder may be used to output the address (position) of one of the matching words.